Type I allergic diseases such as seasonal allergic rhinitis (hayfever), conjunctivitis, allergic asthma and allergic dermatitis represent a major health problem in industrialised countries (Wuthrich et al. (1989) Int Arch Allergy Appl Immunol 90:3-10). It is currently estimated that 15-20% of the population in developed countries are afflicted with some form of allergy.
The major outdoor cause of seasonal hay-fever and allergic asthma is airborne grass pollen (Smart et al. (1982) Clin Allergy 12(1):83-9). The most important sources of grass pollen are common agricultural pasture grasses which have been widely introduced throughout the world. For example, in cool temperate regions, grasses such as Rye-grass, Kentucky bluegrass and Timothy (all belonging to the subfamily Pooideae) are of clinical significance.
Antigen-specific tolerance may be defined as the absence or a reduction in intensity, of one or several immune responses, particularly the responses which are responsible for the detrimental action on the organism, to a specific antigen, in the setting of an otherwise normal immune system.
In order to induce antigen-specific tolerance, therapeutic interventions can involve injection or mucosal administration (e.g. oral administration) of the allergen or of mixture of allergens assumed to be responsible for the allergic disorders. With respect to mucosal administration, the sublingual route, for instance, has been explored for antigen administration in a variety of conditions (see e.g. Bahceciler et al. (2005) Int. Arch. Allergy Immunol. 136:287-294). In case of grass allergy, sublingual grass tablets can be manufactured using one or several extracts made from pollens obtained from grass species. Examples of such tablets are presently sold under the name Grazax® (Phleum pratense pollen extract) by the ALK Abello Company and Oralair® (mixture of pollen extracts from five grass species) by Stallergènes.
Accordingly, there is a need, in particular from quality control organisms or drug agencies, for methods enabling the determination of specific grass allergens in compositions.
Methods known in the art, such as Enzyme-linked immunosorbent assay, are usually time consuming, depend on the availability of specific antibodies and often show a low accuracy. It is therefore an object of the invention to provide an alternative method with improved specificity and accuracy